New -- TTC boy in girl-heavy family

Hi all. My name is Julia, and I have a beautiful 16-month girl. DH and I really want a boy for our next (hopefully not last!) one. Both of our families are very girl-heavy. I grew up in a 1-boy/3-girl family, and DH had a 2-boy/5-girl family. Now our DD has 20 cousins, and only 4 boys in the bunch.

We knew we wanted to TTC a boy from the beginning, because it seems so difficult to get one. We used the Shettles method with the following results: Pregnancy #1 ended in miscarriage and I don't know the gender; Pregnancy #2 gave us our sweet girl, whom we adore.

This is what we did while unsuccessfully TTC a boy (sorry if there's TMI here!): charted and timed BD as close to ovulation as possible; DH drank a Dr. Pepper right before BD; I O'd first (though not during intercourse - doesn't work for me), and again after DH; used Pre-seed lube. I am absolutely certain we got the timing right. I used ovulation tests, my CM was the perfect consistency, we BD'd that night, and the next morning I had ovulated & my temp was up. I don't know how to time it better!

Anyway, we'll be TTC again this summer. Any thoughts on what I could do differently this time? TIA!